Excess crankcase pressure....Help

I’m a new member looking for help. I Love my 97 XK8, but I have spent far more hours working on it than actually driving it. The newest problem is that within 100 miles of replacing the timing chain guides it BLEW the rear main seal out. It dumped all 7 quarts in 1 mile. The oil is not dripping out, it is blasting out. This seems like excessive crankcase pressure. Is it possible that I connected something incorrectly, or could something have plugged up?
Help. Any advice appreciated, my wife wants this car back on the road soon.

Not sure exact configuration of your car, but generally there is a PCV (positive crankcase ventilation) valve, that is routed with hoses, between the intake air filter and the engine block, for the purpose of relieving the pressure caused from the underside of the pistons - when this PCV path is blocked your symptoms appear- check your PCV valve for it may be in need of replacement.

The left cam cover has a PART LOAD BREATHER and the right cam cover has the FULL LOAD BREATHER.

There is a TSB (600-03 amended) for the procedure to check and clean the part load breather orifice.

600-03am3 Part-Load Engine Breather.pdf (114.2 KB)


That was my first thought as well. I could not find one, and while researching it I saw on another forum that 97 XK8’s do not have a PVC valve, but thank you for responding.

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motorcarman, thank you, that sounds easy enough to do, I will try it.

Looks like what motorcarman posted (thanks) takes the place of the old PCV valve system to help with crankcase pressure - if you can, post an update of your results after following TSB.

It is an 97 … do a compression test
Is it the original motor?
If so and how many miles?
Lovely early car but they go …
B. O. O. M. Very fast from one of two things
100,000 mile limit or nickelsiil engine!
Do a compression test but the key is how many miles if your near 100,000 that’s about it my friend
Ps the guys are right with the tsb but…
Do a compression test

Hi all newby here, interested to hear of the 100,000 mile life or failure of nikeseal bores on these engines, I have a 2000 xkr on 130,000 + and 1998 xk8 on 110,000 miles and they are both running sweet as a nut, where did you get this information from.

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Well you are one lucky camper…
Change the tensioners and chains , clean out the blow pipe and refresh the transmission every 30,000 and you will be happy.
Overall by 2000 alot of issues were resolved.
If you bought the cars new and had it all this time , Congrats.
If not , you might have a replacement engine along the way.
Very common, 97,98 were the worst of the bunch but , it rolls across to 2000, beyond 2000 with tensioners and chains, steel sleeves came around the 2000 model year or so.

The 100,000 mile fable is ‘just-that’, a fable.
The failures were mostly due to high sulfur fuel and many manufacturers suffered the same fate.

BMW engines in the 1990s were commonly failing also from the nikasil liners.

The only other thing that will absolutely destroy the engine it OVERTEMP.

The aluminum pistons swell and scrapes the lining away FAST.

The Nickel Silicon lining is actually harder and more durable that a steel or cast iron liner.
I have a few customers with over 250,000 miles on the pre-August 13, 2001 engines.

The high sulfur fuel is a thing of the past due to EPA regulations so no worry about that.

Keep oil and coolant in the engine and it should last a LONG TIME.


Hempstead Jaguar was replacing 2 a week
It was a BIG warranty problem
That’s why a 1998 xj8 or close xk8 goes for peanuts if they are high mileage

Both original engines and both had timing chain tentioners done, oil and filter done on XKR just need to do it on 8, only real problem is the tin worm the XKR rear quarters are due repair due to the fact that when i got it,(10 years or so) i took a look at the inside of the rear wings in that area and found that the air flaps had allowed all sorts of dirt/sand to deposit itself in the bottom of the rear wings to a depth of 3 inches, this is what started the rot but managed to keep under control until now, sorry for diverging

Great ownership!.
I loved my 2001 XK8 convertable, Silver /black/black top.
Geoff Lawson was a friend, he did a great job on that car…
That was a wonderful period and last of the FAMILY feel at Jaguar.
Enjoy that ride!

Well, I have an update, and some answers to some questions asked above. My 97 XK8 has 63,400 miles, It is not the original engine, it has 62k miles on it, I can explain what happened if anyone cares. I have changed the tensioners and timing guides, replaced water pump, thermostat and housing, all preventatively. I cleaned 74 pieces of plastic out of the oil pickup left by a previous owner. The part load breather was indeed plugged solid, thank you guys for the advice. Hard to imagine that tiny orifice could vent that much pressure, but it will be cleaned every oil change. This weekend I dropped the transmission and the rear main seal was blown almost completely out of the engine block, easy to grab and remove by hand. The new seal is in and the car is almost back together. Someone on here said they did this job in 3.5 hours, I wish you were here, I won’t say how many hours it’s taken so far.
Every time I figure I’m done and the car should now be trouble free, something else pops up. There’s many years of experience with these cars on this forum, is there other maintenance tips like the breather vent that I should be addressing? I LOVE this car, but I’ve had enough of working on it more than driving it. I’m planning on doing the compression check when it’s back together, but it runs very strongly.
Thank you guys for the help, much appreciated!!

Dave I’ve been down this road so many times
The whole xk8 97 to 2004 or so along with xj8 1998 to 2003 ish were built to 100,000 miles
Some don’t want to hear it but
Your first engine probably blew just about the same time
I love them and they are great but your hitting the cross road .A Porsche Cayman or old 911 will last forever with no issues
It’s your call or just lease a new F Type
It’s your call you will never get back what you put in at this point
Good luck

I was told by both the dealers in Fife, WA & Victoria, BC that 2001 was the new engine in all cars, possible that late numbered 2000
had it as well. New engine was the preferred engine for replacement.

If you were going to put low miles on it, I’d vote for the F-Type also! Got passed by a F-Pace on the freeway today in my Range
Rover Sport, good thing we were in very crowded traffic.

Bob Allen